New York Sen. Chuck Schumer says he gave his hechsher to Chuck Hagel’s bid for defense secretary after the nominee convinced him that he’d toughened his views on Iran, Hezbollah and Hamas.

Yesterday, Bulgaria blamed Hezbollah for a terror attack there last year — the bombing of a tourist bus that killed five Israelis and a Bulgarian driver. Sofia’s declaration is highly embarrassing for the European Union, which has resisted labeling Hezbollah a terrorist outfit. But it should also be embarrassing for Schumer and Hagel.

Back in 2006, the two senators were on opposite sides when Schumer signed, and Hagel refused to sign, a letter urging the EU to label Hezbollah terrorists. Schumer says he doesn’t hold that against Hagel, because the latter assured him that his views have changed since “five, six years ago.”

As Schumer explained it, Hagel told him the reason he’s changed is that “Iran is a different country. Hezbollah and Hamas are different organizations.”

Really? Different? In 1983, a Hezbollah bombing in Beirut killed 241 US servicemen. In the 1990s, a Hezbollah attack on the Israeli embassy in Argentina killed 29 and another on a Jewish center there killed 85. In 2006, Hezbollah fired countless rockets into northern Israel.

This record was what Schumer and 87 other senators were referring to when they invoked Hezbollah’s “long history of terrorist attacks around the world.” If Hagel was so blind to Hezbollah then, what makes anyone think he’d be any better today — the Bulgarian tragedy notwithstanding? Ditto Iran, Hamas and other enemies of the United States he’s been soft on.

At least in public, Hagel has changed his tune on these issues. But his sad, incoherent performance before the Senate last week only heightens questions about what he really believes, and how he would behave if confirmed as defense secretary.

As for Schumer, if he wants the rest of us to buy the idea that he finds persuasive the argument that Hezbollah is a different organization from the one it was five or six years ago, Hagel’s not the only one with credibility issues.